Not all men are equally vulnerable to habitual porn use. For some men, however, Dr. Victor Cline, clinical psychologist at the University of Utah, identified four stages of viewing pornography following initial exposure. They are: (2)

Addiction - The desire and need to keep coming back for pornographic images.

Escalation - The need for more explicit, rougher, and more deviant images for the same sexual effect.

Desensitization - Material once viewed as shocking or taboo is seen as acceptable or commonplace.